Documentation for the Harman Kardon media player (#7581)

* Documentation for the Harman Kardon media player

* Review fixes

source/_components/media_player.harman_kardon_avr.markdown

@@ -0,0 +1,52 @@
+---
+layout: page
+title: "Harman Kardon AVR Network Receivers"
+description: "Instructions on how to integrate Harman Kardon AVR Network Receivers into Home Assistant."
+date: 2018-11-20 09:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: harman_kardon.png
+ha_category: Media Player
+ha_iot_class: "Local Polling"
+ha_release: 0.85.0
+---
+
+The `harman_kardon_avr` platform allows you to control Harman Kardon Network Receivers from Home Assistant.
+
+Supported devices:
+
+- Harman Kardon AVR-151S
+- Other Harman Kardon AVR receivers (untested)
+
+To add a Harman Kardon Network Receiver to your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+media_player:
+  - platform: harman_kardon_avr
+    host: IP_ADDRESS
+```
+
+{% configuration %}
+host:
+  description: IP address of the device, e.g., 192.168.1.32.
+  required: true
+  type: string
+name:
+  description: Name of the device. If not set, Harman Kardon AVR is used.
+  required: false
+  default: Harman Kardon AVR
+  type: string
+port:
+  description: The port to talk to the receiver. If not set, 10025 is used.
+  required: false
+  default: 10025
+  type: integer
+{% endconfiguration %}
+
+A few notes:
+
+- The newest firmware automatically shuts down the AVR after a certain amount of time. The AVR is then not available on the network anymore, so the 'on' command will not work.
+- The AVR has no endpoints to determine the volume, muted, playing etc., so if the remote control is used, HA will not know the new states of the device.